1. Field of the Invention
The present invention relates to mammography apparatuses that obtain X-ray images of mammary specimens using X-ray imaging.
2. Description of the Related Art
Mammography apparatuses that obtain X-ray images of mammary specimens using X-ray imaging include mammography apparatuses that use semiconductor two-dimensional image detectors. These are configured mainly with an X-ray source, a pressing panel for pressing the breast, a two-dimensional X-ray image detector that holds the breast and images an intensity distribution of transmitted X-rays. Two-dimensional image detectors are produced by combining phosphor, which converts the X-rays to visible fluorescence, and a semiconductor two-dimensional image detector (see Japanese Patent Laid-Open No. 08-238233 for example).
Some mammography apparatuses use a grid to suppress scattered X-rays (see Japanese Patent Laid-Open No. 2005-013344 for example).
Furthermore, some apparatuses perform imaging with the X-ray image and an ultrasonic image of the breast under a same pressing condition. For example, infrared rays are used in a sensor that detects a position of an ultrasonic probe in regard to these apparatuses. The breast is pressed in a same manner for obtaining the X-ray image and for obtaining the ultrasonic image, and therefore as a result it is possible to combine the ultrasonic image and the X-ray image (see Japanese Patent Laid-Open No. 2003-260046 for example).
Furthermore, techniques have been proposed (see Japanese Patent Laid-Open No. 09-505407 for example) in which a breast image is captured by irradiating near infrared rays onto a breast through a breast compressing panel and collecting transmitted light using optic fibers.
Further still, techniques have been proposed (for example, see Sergio Fantini et al, “Using Near-Infrared Light To Detect Breast Cancer,” Optics & Photonics News, November, 2003) in which a near infrared image of a breast is obtained by causing a plurality of amplitude-modulated near infrared rays to be incident on a single optic fiber then transmitting this onto the breast and performing homodyne detection on the transmitted near infrared rays.
In breast cancer diagnosis using mammography apparatuses, reproducibility of positioning between the imaging apparatus and the breast is sometimes required for cytology and histology in a case where a positive result is doubted or during postoperative observations over time.
However, conventional mammography apparatuses do not have a positioning function.
On the other hand, although there are cases where near infrared images are effective in discovering tumorous cancer, which is a weak point for X-ray images, there is a problem in that it has not been possible to achieve a correspondence between the positions of the morbid portion discovered in the near infrared image and the X-ray image.